'91 Merc 115 Rectifier Replacement

brobrad

Petty Officer 1st Class
Joined
Jun 19, 2009
Messages
246
I have a 1991 mercury 115 4cyl that runs great. I just had to replace the switch box so i'm replacing regulator and rectifier just as a precaution as i'm taking it out of town on vacation 500 miles away and i won't to eliminate as many issues as possible. I got the sierra replacement rectifier. The OEM had the posts labeled red(alt), yellow, grey. The replacement rectifier has three posts in an offset configuration in lieu of the linear oem setup. The new one only has a + mark on one post. Not sure how to wire the other two up and i've found no info on it. Any help???
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,605
The "+" marking goes to the battery connection. It is the DC positive output terminal. The other two are inputs from the stator. So pick one and attach the tach gray wire to it and happy boating...
 
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